1. Field of the Invention
This invention generally relates to direct current (DC)-to-alternating current (AC) power inversion and, more particularly, to a system and method for efficiently managing to use of DC-to-AC power inversion for a client using metered AC power from a utility.
2. Description of the Related Art
DC-to-AC power converters or inverters tend to have an efficiency curve that peaks at an optimum power output level, with a relatively low efficiency at high power settings. Typical load-following peak management systems track the load when it is above a target demand level. Thus, the power inverter may spend a significant amount of time at low efficiency power settings. This results in a waste of DC energy that is being supplied to hold down the AC electric demand. When the source of DC energy is a battery, this inefficiency results in a waste of limited battery capacity.
Electric peak demand systems that track the AC demand continuously attempt to hold the AC demand at or below the targeted peak demand level. Typically, an electric utility company only measures the demand in 15-minute block periods with the measurements being recorded at minutes 00, 15, 30, and 45. Since the instantaneous demand can vary significantly, the actual peak demand of a continuously rolling 15-minute period may occur in between the power company's measurement times. If the peak demand happens to occur during the measurement time, the client's billing rate is adversely affected.
It would be advantageous if an electric utility client could manage their AC usage, using a DC-to-AC power inverter, to minimize their demand from the utility at measurement times, thus minimizing their billing expense.